Abstract

Backscattering and diffraction results are presented for the effects of an interfacial or a surfaceMo layer on the formation of Ti-silicides during solid-state interaction between Ti films and Si substrates. It is shown that the interfacial and surfaceMo are fundamentally different in their involvement in the Ti-silicide formation. The interfacial Mo induces the formation of C40 at the interface adjacent to the Si substrate already after annealing at 550 °C, in agreement with our previous results. Hence, the desired C54 can grow directly on top of the C40 at relatively low temperatures as a result of the template effect. The surfaceMo is, however, found in a metal-rich silicide presumably at 550–600 °C, which eventually converts to upon annealing at higher temperatures. Underneath this metal-rich silicide lies a fully developed C49 layer. Consequently, the formation of C54 in the presence of surfaceMo follows the usual path of the C49–C54 phase transition. This important difference in the participation of Mo in the silicide formation spreads doubts about the validity of using interfacial Mo versus surfaceMo to study the dominant mechanism(s) responsible for the enhanced formation of C54